The sum of the measures of the angles of a quadrilateral is:
(n - 2)180 = (4 - 2)180 = 2(180) = 360
That means
x + y + z + w = 360
Choice B is incorrect because it only adds 3 of the angles, not all 4.

mathstudent55

2 years ago

Yes, you are correct. The answer is C.

mathstudent55

2 years ago

Notice that both choices C and D have angles adding up to 180.
In choice C, x and z are opposite angles, so their measures do add up to 180.
In choice D, angles z and w are not opposite angles, so we don't know if their measures add up to 180. Besides, there is no mention of angle x in choice D, so D cannot be correct.